Charles elvidge



(No man. 2 sheets-sheet 1;

No. 524,779. Patented Au 21, 1894 cams PETERS co. PNUYOJJTHU. wnsumomn,u c.

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2 Sheets-Sheet 2.

C. ELVIDGE; AUTOMATIC OFPSETVMBGHANISM FOR SAWMILLGARRIAGES.

(No Model.)

No. 524,779. Pa,tented Aug. 21, 1894..

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UNITED STATES EN O FI CHARLES ELVIDGE, OF OAKLAND, CALIFORNIA, ASSIGNOROF ONE-HALF 'ro JOHN D. EBY, OF SAME PLACE.

AUTOMATIC OFF SET MECHANISM FOR SAWMILL-CARRIAGES.

SPECIFICATION forming part of LettersPatent No. 524,779, dated August21, 1894.

Application filed March 2 1 894.

To, all whom it may concern.-

Be it'known thatI, enlar es ELVIDGE, a sub ect of the Queen of GreatBritain, resid- 1ng 1n Qakland, Alameda county, State of Oa11forn1a,have invented an Improvement 1n Automatic Offset Mechanism for Sawmill-Carriages; and I hereby declare the following to be a full, clear, andexact des'criptionof the same.

My invention relates to the class of mechanisms for automaticallyoffsetting the carriages of band-saw mills, and it consists of theconstructions and combinations of de Vices which I shall hereinafterfully describe and claim. 1 i

o The object of my invention is to provide a slmple, durable andaccurately operating, effectlve offset mechanism for saw mill carriages,the particular advantage of which is that not being dependent upon thecarriage axles, its operation can be relied upon to take place at propertimes.

Referring to the accompanying drawings for a more complete explanationof my invent1on, Figure 1 is a View of the bottom of the carriageshowing the working mechanism. Fig. 2 is a side view of the same. Figs.3 and 4 are enlarged details of construction.

A is the log carriage mounted upon axles B in such manner that it can bemoved thereon between the hubs of the wheels 0, in the usual manner ofthese offsetting carriages. The wheels travel on the tracks D as usual.Under the carriage and supported therefrom is a transverse shaft E,having a screw-thread e, which is seated in a nut a of carriage A. Uponthe shaft E is firmly set a cam 0r seg-, ment F, which is adapted toimpinge upon some fixed surface, either the millfioorflor a speciallylocated rail, or as here shown upon. the rail D. The length of thecircular or full round portion of the cam or segment is proportioned tothe amount of movement of the screw-thread required for the offsettingand return of the carriage. In operation, as the carriage feeds forward,the then lowest point of the cam'or segment moves forwardly over therail upon which it, impinges, thus transmitting no movement. But at theend of the feed,'and just as the carriage starts to gig.

back, the traction of the cam or segment on seen No. 502,135. (Nomodel.)

the railD, will turn it upon its full round portion, until its otherpoint is reached, which being presented forwardly will move over therail on the return. But in thus turning, the screw-shaft E, operating inthe nut a, will immediately offset the carriage, and the latter will beheld offset until the return limit is reached. Then the cam or segmentwill, upon the startingof the feed, turn again and will thus, throughscrew shaft E return the carriage to thesaw line. In practice, a shaft Eand cam F will be placed near each end of the carriage, and in order, tooperate them in unison, they will be connected by the rod G,

secured to an arm 9 extending downwardly from the shafts.

Itis obvious that in case it be deemed advisable to employ a tractioncam or segment on each side of the carriage, the shaftsE may be extendedacross the entire width of the carriage. The cams or segments arelimited and cushioned in their movements and accurately returned andheld to their impingement on the rail by reason of their ends coming in'contact with the spring-controlled buffer rods or rubber cushions Imounted in the carriage. I have found in practice that if the cams areallowed to slide upon the rails,

there will" be an injurious wear, I therefore journal rollers b in theends of the segments. These rollers may have grooved peripheries to fitthe rails and when the segments have been turned so as to' ofiset thelog carriage in either direction, and the carriage is then moved alongthe track, these rollers travel upon it and rotate so that thereis nofrictional wear upon the segment or the rail. When the segment is to beturned to rotate the screw, it is necessary to lock the wheels so thatthere will be the necessary frictional contact with the rails to turnthe segment.

This is effected'by pawls c pivoted so that the ends touch theperipheries of the wheels, and are pressed against them by springs dwith sufilcient force to lock the wheels when the carriage commences tomove in the direction which should rotate the segment. This insuressufficient friction between the wheel and rail to begin the rotation ofthe segment, and when its own periphery forms contact with the rail, itcompletes the movement.

seam-9 The wheels at each end of the segments thus form a bearing uponthe track, and rotate freely when the segments have turned the length oftheir arcs, but are looked as soon as a movement of the carriage in theoppoposite direction commences so as to insure a rotation of thesegments in-the opposite direction.

In order to take the side strain off the segments and rails, I haveshown the nut a in which the screw 6 turns, connected with an arm m, theends of which have sleeves n fitting and turning loosely upon the wheelaxles. Collars are fixed to the axles upon each side of the sleeves soas to prevent their moving longitudinally upon the axles. When the screwturns in the nut, the carriage will be moved sidewise sufficiently tooffset it to and from the saw as previously described.

In order to accurately adjust the cams or segments to their traction onthe rails, the shafts E near their outer ends are mounted in adjustableboxes J, the lower sections of which are adapted to be raised or loweredby means of the screws j.

To look the cams or segments at any time,

as, for example, when it is necessary to back the saw out of the cut,the swinging links K on the carriage are dropped down over arms gextending upwardly from, and secured firmly to, the shafts E. Inpractical construction, thearms g and 9 will be formed together with ahub g as a single casting and secured to the shaft.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

1. An offsetting mechanism for saw mill carriages consisting of a cam orsegment mounted on the carrier and having rollers mounted within it,said rollers being freely rotatable in one direction andlocked againstrotation in the opposite direction, and power transmitting connectionsfrom said cam or segment to effect the offset and return of the carriageat the beginning of the gigging and feeding movements respectively.

2. An offsetting mechanism for saw mill carriages, consisting of a shaftmounted on the carriage, a cam or segment fixed on the shaft andprovided with anti-friction rollers freely rotatable in one directionand locked against rotation in the reverse direction, said rollersadapted to impinge against a fixed surface whereby the cam or segment isoscillated by traction, and the shaft turned, and power transmittingconnections from said shaft to effect the offset and return of thecarriage at the beginning of the gigging and feeding movementsrespectively.

3. An offsetting mechanism for saw mill carriages, consisting of a shaftmounted on the carriage and provided with a cam or segment havinganti-friction rollers mounted therein to freely rotate in one directionand to be held against rotation in the opposite direction whereby thecam or segment is oscillated by traction, and the shaft turned, andpower transmitting connections from said shaft to effect the offset andreturn of the carriage at the beginning of the gigging and feedingmovements respectively, consisting of a screw thread on the shaft and anut on the carriage in which the thread is seated.

4. In an offsetting mechanism for saw mill carriages, the combination,of a traction cam or segment carrying anti-friction rollers adapted torotate'free] y in one direction and to be held against rotation in theopposite direction, and to engage a fixed track surface, the screw shaftupon which the cam or segment is mounted, the nut on the carriage inwhich said shaft is seated, and the adjustable box in which the shaft ismounted whereby the cam or segment may be adjusted.

5. In an offset mechanism for saw mill car riages, the combination, ofthe traction cam or segment provided with anti-friction rollers freelyrotatable in one direction and held against rotation in oppositedirection, and the buffer rods or rubber cushions for limiting themovement of the cam or segment and returning it to its tractionimpingement.

6. In an offsetting mechanism for saw-mill carriages, the combination,of the screw shaft seated in a nut on the carriage, the traction cam orsegment provided with anti-friction rollers freely rotatable in onedirection and locked against rotation in the reversedirection, the arm9' of the shaft, and the drop-link for engaging the arm and locking theshaft and its cam or segment.

7. An offsetting mechanism for saw-mill carriages consisting of shaftstransverse to the carriage with screw threads turning in a nut upon thecarriage, segments fixed to the shafts adapted to impinge upon a fixedtrack or surface whereby they are rotated the length of their arcs andthe screws advanced in the nuts when the carriage travels in eitherdirection along the track, and wheels journaled in the segment ends toimpinge and travel upon the track after the segments reach the limit oftheir oscillation whereby wearing friction upon the segments isprevented.

8. In an offsetting mechanism for saw-mills, transverse screw shaftsturning in nuts upon the carriage and adapted to move it to one side orthe other with relation to the saw, segments fixed to the screw shaftsand having their circular peripheries traveling upon fixed tracks sothat the longitudinal movements of the carriage rotate them and thescrews 2. fixed distance, wheels journaled in the se ment ends andadapted to travel freely upon the tracks and prevent friction when thesegments have completed their rotation in either direction, and lockingpawls or devices whereby the wheels are prevented from rotation when thecarriage begins a reverse movement, substantially as described.

9. In an offsetting mechanism for saw mill carriages, transverse screwshafts having circular segments fixed to them, anti-friction rollersmounted in the segments and freely upon the axles between which thesleeves are rotatable in one direction, and adapted to imheld andprevented from end movement when pinge upon afixed track by the frictionon the screws turn in the nuts.

which said segments are rotated the length In witness whereof I havehereunto set my i 5 of theirarcs by the movements of the carriage hand.

along the track, means for preventing the rotation of the rollers in areverse direction, CHARLES ELVIDGE' nuts through which the screws pass,bars to Witnesses: which the nuts are fixed, having sleeves LINCOLNSONNTAG, IO loosely surrounding the axles, and collars J. STURGEON.

